ClickHouse/src/AggregateFunctions/AggregateFunctionQuantile.cpp
2022-10-19 08:05:09 +00:00

72 lines
3.5 KiB
C++

#include <AggregateFunctions/AggregateFunctionQuantile.h>
#include <AggregateFunctions/QuantileReservoirSampler.h>
#include <AggregateFunctions/AggregateFunctionFactory.h>
#include <AggregateFunctions/Helpers.h>
#include <DataTypes/DataTypeDate.h>
#include <DataTypes/DataTypeDateTime.h>
#include <Core/Field.h>
namespace DB
{
struct Settings;
namespace ErrorCodes
{
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
}
namespace
{
template <typename Value, bool float_return> using FuncQuantile = AggregateFunctionQuantile<Value, QuantileReservoirSampler<Value>, NameQuantile, false, std::conditional_t<float_return, Float64, void>, false>;
template <typename Value, bool float_return> using FuncQuantiles = AggregateFunctionQuantile<Value, QuantileReservoirSampler<Value>, NameQuantiles, false, std::conditional_t<float_return, Float64, void>, true>;
template <template <typename, bool> class Function>
AggregateFunctionPtr createAggregateFunctionQuantile(
const std::string & name, const DataTypes & argument_types, const Array & params, const Settings *)
{
/// Second argument type check doesn't depend on the type of the first one.
Function<void, true>::assertSecondArg(argument_types);
const DataTypePtr & argument_type = argument_types[0];
WhichDataType which(argument_type);
#define DISPATCH(TYPE) \
if (which.idx == TypeIndex::TYPE) return std::make_shared<Function<TYPE, true>>(argument_types, params);
FOR_BASIC_NUMERIC_TYPES(DISPATCH)
#undef DISPATCH
if (which.idx == TypeIndex::Date) return std::make_shared<Function<DataTypeDate::FieldType, false>>(argument_types, params);
if (which.idx == TypeIndex::DateTime) return std::make_shared<Function<DataTypeDateTime::FieldType, false>>(argument_types, params);
if (which.idx == TypeIndex::Decimal32) return std::make_shared<Function<Decimal32, false>>(argument_types, params);
if (which.idx == TypeIndex::Decimal64) return std::make_shared<Function<Decimal64, false>>(argument_types, params);
if (which.idx == TypeIndex::Decimal128) return std::make_shared<Function<Decimal128, false>>(argument_types, params);
if (which.idx == TypeIndex::Decimal256) return std::make_shared<Function<Decimal256, false>>(argument_types, params);
if (which.idx == TypeIndex::DateTime64) return std::make_shared<Function<DateTime64, false>>(argument_types, params);
if (which.idx == TypeIndex::Int128) return std::make_shared<Function<Int128, true>>(argument_types, params);
if (which.idx == TypeIndex::UInt128) return std::make_shared<Function<UInt128, true>>(argument_types, params);
if (which.idx == TypeIndex::Int256) return std::make_shared<Function<Int256, true>>(argument_types, params);
if (which.idx == TypeIndex::UInt256) return std::make_shared<Function<UInt256, true>>(argument_types, params);
throw Exception("Illegal type " + argument_type->getName() + " of argument for aggregate function " + name,
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
}
void registerAggregateFunctionsQuantile(AggregateFunctionFactory & factory)
{
/// For aggregate functions returning array we cannot return NULL on empty set.
AggregateFunctionProperties properties = { .returns_default_when_only_null = true };
factory.registerFunction(NameQuantile::name, createAggregateFunctionQuantile<FuncQuantile>);
factory.registerFunction(NameQuantiles::name, { createAggregateFunctionQuantile<FuncQuantiles>, properties });
/// 'median' is an alias for 'quantile'
factory.registerAlias("median", NameQuantile::name);
}
}